Valheim Incompatible Version Fix for Dedicated Servers

The Valheim "Incompatible version" error means your game and the server are not on the same build. Almost always, Valheim updated and either the server or one player has not caught up yet. The fix is to update whichever side is behind and restart. This guide shows how to check which one it is, and covers the less obvious causes: the public test branch, Game Pass lag and mods.

Quick fix

1. Fully close Valheim and let Steam finish any pending update. If none shows, right click Valheim in your library, choose Properties > Installed Files > Verify integrity of game files.
2. Update the server. Self hosted: run the SteamCMD update below and restart. Hosted: restart the server from the control panel.
3. Try joining again.

For a self hosted server, the update command is the same one you installed with. The dedicated server is app ID 896660:

steamcmd +force_install_dir C:\valheim-server +login anonymous +app_update 896660 validate +quit

Run it while the server is stopped, then start it again.

Check which side is out of date

Compare two version numbers:

• Your game: shown on the Valheim main menu.
• The server: printed near the top of the server log or console when it starts.

If the server number is lower, update the server. If yours is lower, update your game. If they match and you still see the error, the problem is mods or a beta branch, covered below.

Common causes of "Incompatible version"

A patch just came out

Iron Gate often ships hotfixes in the days after a big release like Valheim 1.0. Steam updates players automatically, but a dedicated server only updates when someone runs SteamCMD or restarts a host that updates on boot. After any patch, update the server first, then tell your crew to restart their games.

Someone is on the public test branch

If one player opted into Valheim's public test beta in Steam, their game is on a newer build than a normal server. In Steam, right click Valheim, open Properties > Betas and set it back to None, then let the game update. The reverse also happens: if the server was installed on a beta branch, players on the normal branch cannot join.

Game Pass or Microsoft Store players are behind

Xbox and PC Game Pass versions sometimes receive a patch hours after Steam. If only your Game Pass friend gets the error, check for updates in the Xbox app or Microsoft Store and wait until the update is out there too. Keep crossplay on the server so those players can join at all.

Mods changed the version check

BepInEx mods can cause version errors in two ways:

• A mod is missing or a different version on one side. Many mods check that the server and each player run the same version and refuse the connection if not. The message may name the mod, or it may just say incompatible.
• A mod broke after a game update. Mods often need their own update after a Valheim patch. Until the author updates it, a modded server and a vanilla game disagree.

The fix is a shared mod manager profile. In r2modman or Thunderstore Mod Manager, export your profile as a code and have everyone import it, so every player has exactly the server's mod list. Remember that mods do not work for console players.

Your old launch script overwrote the new files

On a self hosted server, if you edited start_headless_server.bat or start_server.sh directly, an update can reset it or you may be running an old copy from another folder. Keep your start script under a new name, and run the update in the same folder the script starts.

After you fix it

Once versions match, back up the world before you play. Big updates occasionally change the save format. Valheim 1.0 moved worlds to a new folder format and converts old .db and .fwl files the first time they load, which can take several minutes. Do not stop the server during that first load.

Incompatible version on a hosted server

On GamezServers you do not run SteamCMD yourself. Restart the server from the control panel and it installs the current version of the game on the way up. Take a backup first with the Backup button, so a patch that breaks a mod never costs you the world. If players on the same server still see the error after a restart, the mismatch is on their side: a pending Steam update, a beta branch or a missing mod.

FAQ

Why does Valheim say incompatible version when my friend and I are both updated?

Usually one of you is on the public test branch, or a mod differs. Compare the version numbers on the main menu and in the server log, and check your Steam Betas setting.

How do I update my Valheim dedicated server?

Stop it and run steamcmd +login anonymous +app_update 896660 validate +quit with your install folder, then start it again. On a hosted server, restart it.

Can I stop Valheim from updating so my mods keep working?

Not for players on Steam, since the game updates automatically and an old server would lock everyone out. Update the server and wait for mod authors to catch up, or pause mods until they do.

Does "Incompatible version" delete my world?

No. It only blocks the connection. Your world is untouched until someone joins with a matching version.

The easy way

Keeping a server in step with every Valheim patch is one more job on top of playing. A hosted server has one click backups and updates on restart, and it stays online when you log off. See Valheim server hosting, or read how to host a Valheim server to see how setup works.